Origin of the large south-east cold front in Abell 2142

Determine whether the large south-east cold front observed about 1 Mpc from the center of Abell 2142 is produced by the long-term evolution of core sloshing structures or by an intermediate, more violent off-axis merger event that triggered sloshing.

Background

Abell 2142 hosts multiple cold fronts associated with extreme core sloshing, including an outer front located approximately 1 Mpc to the south-east of the cluster center. While several signatures of interaction and sloshing have been identified in X-ray data, the physical origin of the outermost front remains ambiguous.

Two leading scenarios are discussed: (i) the cold front arises from the natural long-term evolution of small-scale sloshing structures that originated in the cluster core, or (ii) the front was generated by an intermediate merger that was more violent than typical off-axis mergers known to trigger sloshing in cool-core clusters. Resolving this ambiguity is important for understanding the dynamics and merger history of Abell 2142 and for constraining models of cold-front formation in cluster atmospheres.